Evaluation of Certain Probiotic Bacteria for Biosynthesis of Vitamin B Complex in Cultured Milk

摘要

Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce vitamin B-enriched fermented products and/or develop probiotic supplements that accomplish vitamin B biosynthesis. Nine available probiotic cultures were examined for their ability to synthesize B vitamins. In order to yield comparable assaying conditions, heat treated whole milk, was inoculated individually with nine strains, and used for cultured milk production. The levels of thiamin (B1), riboflavin (B2), niacin (B3), pyridoxine (B6), folic acid (B9) and cobalamin (B12) were determined. With all cultures vitamins B2 and B3 were enriched during fermentation. The biosynthesis of B9 and B12 vitamins were significantly below the level for B2 or B3 content, but were not as low as that with B1 and B6 vitamins. Fermentation did not significantly modify vitamin B1 or B6. The levels of B vitamins with L. paracasei 4560 were lower than those in L. reuteri 14171, L. helviticus 118, B. bifidum Bb12 and L. acidophilus La5. Moderate levels were with L. casei DSM2011, L. rhamnosus 442, B. longum 146 and S. thermophilus. Niacin, which had risen to 59 fold with L. paracasei 4560, was elevated to 200- fold in the L. helviticus 118, L. casei DSM2011 and B. bifidum Bb12 cultured milk. In contrast, thiamine was reduced in B. bifidum Bb12 to one quarter. The viability of the probiotic bacteria and pH values were also determined.